Resistors Definition and 603 Threads

Homework Statement I am given this circuit...

I am playing with Arduino and LEDs at the moment. LED needs a resistor to limit current, that's clear. However, all examples I see use separate resistor for each diode. As far as I can tell electrically (in terms of limiting current) it shouldn't matter much whether we use single resistor for...

Homework Statement We are suppose to make a lab report about and experemint that we did in physics lab. It consisted of drawing equipotential lines in a overbeck electric field mapping apparatus. Different desing plates were used, each having conductors, some were circular and other where...

Homework Statement Here: http://imgur.com/a/5rRgu 2. Homework Equations V=IR The Attempt at a Solution Basically from reversing the polarity of the cell and looking at a mirror image of the circuit i got the following relationships. First I(9)=0 then I(1)=-I(4) I(5)=-I(6) I(7)=-I(8). I...

Homework Statement From the picture below, calculate the net resistance between points A and B if ##R_1=12## ##R_2=3.75## Homework Equations 3. The Attempt at a Solution [/B] I cannot think of any way but to find the equivalent resistance od ##R_1## and ##R_2## and add them up but since there...

The goal of this problem is to find the equivalent resistance of all the resistors. Each resistor shown in the image has a conductance of 1 mS which I believe is equal to 1000 ohms. I attached a picture of the circuit diagram in which I show some of my work in order to convey my erroneous...

Homework Statement The overall resistance of the circuit is 12.5Ω. Calculate the value of the resistor labelled R in the circuit. Homework Equations 1/R = 1/R1 + 1/R2 R = V/I The Attempt at a Solution I understand that you use the first equation for parallel resistors and the second to...

Homework Statement Find the average currents through resistors R1 and R2 Homework EquationsThe Attempt at a Solution I have a question , how do I analyse this circuit besides solving differential equations using laplace transform which takes too much time, what is really confusing me is the...

Homework Statement for S1,S2,S3,S4 are all closed at the long time find the current in each resistor Homework EquationsThe Attempt at a Solution why I3 is not = i2? the solution of this question is 24-28I1-I212-12=0 7I1-32=3-----(1) 12-12I2-163=0 3I2+43=3 ---(2) I1+I2-I3=0---(3) I1=0.492...

Homework Statement Homework Equations Rparellel=1/R1+1/R2... IR1=R2/R1+R2 x I The Attempt at a Solution I am unsure of how to answer d) and e) using KVL because I count 4 junctions? Where should I start?

Homework Statement Find I1, I2, I3 as well as the voltages across each resistor. R1= 50 ohms R2= 220 ohms R3= 150 ohms Homework Equations Kirchhoff's loop law Kirchhoff's junction lawThe Attempt at a Solution Loop 1: Starting from the negative terminal of the 10V battery (ccw) 10V - 50...

Homework Statement [/B] Sorry for the quality of the image. This is the best I can come up with with my cellphone. What is the current through the 10 ohms resistor? Is the current from left to right or right to left? Homework Equations Kirchhoff's loop law Kirchhoff's junction law The...

Homework Statement What is the current in the 2 ohms resistor? Homework Equations Kirchhoff's loop law The Attempt at a Solution Grounding does not affect how the circuit behaves, so I ignored the ground in and applied the loop law (clockwise from the negative terminal of the 9V battery...

Homework Statement Picture a circuit grounded at the left lower corner. Then as you go up the left side of the circuit, you have a 9V battery. The top left corner is labeled a. Then on the top of the circuit, you have a 2 ohms resistor. Then on the right side of the circuit, you have a 6V...

Homework Statement A 60 W lightbulb and a 100 W lightbulb are placed one after another ( in series, the 60 W battery closer to the positive terminal of the battery) in a circuit. The battery's emf is large enough that both bulbs are glowing. Which is the true statement? A. The 60 W bulb is...

Homework Statement [/B] Homework EquationsThe Attempt at a Solution Applying KCL at the node , assuming current flows from left to right at the 4 ohm resistor: Vo/4 + 10 + 2Vo = 0 OR, is it : Vo/(4+6) + 10 + 2Vo = 0 since the two resistors are in series?

Homework Statement I have the answer to this question, but I'm trying to understand how to do it. It's a simple circuit: https://onedrive.live.com/redir?resid=6CDEB7909E9460BA!57382&authkey=!ALscxM1v2OtHZIg&v=3&ithint=photo%2cPNG (note: Image inserted in-thread by moderator) The questions...

In my electrical engineering textbook, in the section with voltage dividers, it says that after you combine two series resistors, then the output voltage can no longer be defined. It then said that thus the equivalence was made strictly from a voltage source standpoint. I do not understand why...

Hey guys. I just opened up a case from an AC to DC adapter and I noticed a 1kohm resistor in the circuit. I remembered a class I had about voltage supplies and I remember there were diagrams with a transformer, full bridge rectifiers, capacitors and at the end of them there was a resistor. The...

Homework Statement [/B] Three resistors are connected to a real battery. The open circuit voltage of the battery is 4.5 Volts. The voltage across the 5 Ohm resistor is 2.5 Volts. A) What is the voltage across battery terminals? B) What is the internal resistance of the battery? Here's a...

I was reading about ohmic and non-ohmicresistors, but I'm unsure as to what thedifference between them is. I understand that ohmic devices have a constantresistance, meaning the voltage-current graph produced for it will show a straight line and that non-ohmic devices have a changing resistance...

Homework Statement Consider the circuit shown below. a) What is the total power loss for the whole circuit? b) What is the power loss through R1? c) What is the power loss through R2? d) Find the voltage across each of the three resistors. I didn't do this myself. I have no idea what's going...

Homework Statement Full problem statement and diagram is attached. Homework Equations Kirchhoff's rules, ohm's law The Attempt at a Solution So I presume that what I'll be looking at here is the use of Kirchhoff's Rules and Ohm's Law. I do not know how to approach this as I have never come...

Homework Statement A real voltage source can be expressed as an ideal voltage source that is in series with a resistor that represents the inner resistance of the voltage source. This voltage source is a EMF and it is also in series with another resistor. Suppose both the EMF resistor...

Homework Statement We are told that resistor 1 has a resistance of 4700Ω ± 5% and resistor 2 has a resistance of 6800Ω ± 5% and the equivalent series and parallel resistances are to be calculated with an estimate of uncertainty. Homework Equations RSeries = R1 + R2 RParallel = R1 × R2 / R1 +...

My local hobby store says no. I want to draw a full 40 Amps from my power supply to play with a few formulas that give the magnetic field strength as a function of distance and current from a wire. The wire will be car battery cables. I have a calibrated Gauss meter for field measurements...

I measured a bunch of open circuit voltages across a variety of power supplies using a CRO. the signal is just spurious. Adding a resistor across the output of the same power supplies gives the expected trace. I used high and low impedance option which was 10 megaOhms on the CRO leads. What...

Homework Statement Four resistors connected to a battery are shown in the figure (at bottom). The switch S2 is closed and switch S2 is left open. What is the magnitude of the potential difference Vcd Homework Equations Rp= Σ(1/Ri)-1 Rs = ∑Ri V = IR The Attempt at a Solution Seeing as c and d...

Homework Statement When I took intro physics, resistors didn't have polarity. Now, in electrical circuits class, we start seeing resistors with polarity. For example, this diagram in our textbook: My professor insist that this problem had a misprint/typo: the polarity on the 2 ohm resistor...

Homework Statement Find the voltage through the resistors. Homework Equations V=IR P=IVThe Attempt at a Solution Am I doing these correctly? Can I find the voltage across the inductor the way I did it?

A 5μF capacitor is connected in parallel with a 2MΩ resistor and the combination is then connected in series with a 1MΩ resistor through a switch to a 12V battery. Find the time taken for the voltage across the capacitor to rise from zero initial value to 2V after the switch is closed.From what...

Homework Statement 7a from picture Homework Equations V=IR Voltage division The Attempt at a Solution I am not sure how to apply voltage division here. It is a new concept for me and I'm not really sure how to apply it here. voltage division can only be used in series, but these resistors...

Hi, I have been at this problem for days and I can't seem to see what I am doing wrong. Here is the circuit layout along with my work As you can see I am running into problem getting values of current that do not add up equal to zero. My professor has never discussed how adding a wire like...

Im reading this stack exchange question: http://electronics.stackexchange.com/questions/28897/how-to-choose-value-of-resistor-in-voltage-divider So there is a 5V circuit with 2-100 Ohm resistors that yields a voltage drop across the divide of 2.5V. The current through the circuit is 25mA...

Hi. I have to test a couple PSUs (ripple, regulation, etc.) that are rated 12 V 62.5 A. In order to do so, I need a test load; I was thinking about using nine 2 ohm 100 W 5% resistors (about 3 usd) in parallel (giving 0.22 ohm 900 w). Taking into account the tolerance of the resistors, I get a...

Homework Statement Homework Equations -We can re-arrange circuit components into simpler orientations as long as the components' connections to previous nodes are maintained. The Attempt at a Solution -I attempted to re-arrange the loop of three resistors at the upper left region to no...

Homework Statement Do resistors have electric fields inside them? I'm confused because we never say voltage IN resistors. So I was wondering if charges are moving in a circuit with a resistor, would the flow of charge create E fields along the surface of resistors rather than inside...

Homework Statement a 12v dc supply is connected across 2 100k resistors in series.a voltmeter having sensitivity of 10,000 ohms per volt is switched to its 10v range and is connected to its 10v range and is connected to measure the voltage of 1 resistor. Homework Equations 1)sketch circuit...

Let's say I start at the high voltage part of the Emf source on the right and go counter-clockwise; the first thing I hit is the 10 Ohm resistor, and the current would not split up the junction because the wire is open-ended, correct? So the next thing I would hit is the 8 Ohm resistor, then the...

Homework Statement Combine the resistors into one single resistor Homework Equations Resistors in parallel = 1/1/R1 + 1/R2 +1/R3... Resistors in series = add The Attempt at a Solution I have two ways of getting the resistance. One is by saying that the 80ohm is parallel 20ohm and then...

Homework Statement A circuit is constructed with five resistors and one real battery as shown above right. We model. The real battery as an ideal emf V = 12 V in series with an internal resistance r as shown above left. The values for the resistors are: R1 = R3 = 57 Ω, R4 = R5 = 75 Ω and R2 =...

why does the current divide through parallel resistors? In parallel both resistors have the same potential difference. So how does the charges know that they must go into the resistor with less resistance than other resistor? (sorry my bad english)

For example, the simplest case n=3 I am even stuck on much less the general problem we can start with that and evidently it may be able to be soled with only two or three resistors if you are clever Also we are not allowed to use op amps only resistors and we are given two voltage sources...

Homework Statement I want to plot ##I_C## versus ##V_{CE}## curves for the following: To do so, I need to find appropriate values for ##R_C, R_B## and ##R_1## in the active region. Note that ##R_2## is a potentiometer. Homework Equations ##I_C = 1 mA## ##V_{BE} = 0.7 V## ##\beta = 150##...

Homework Statement http://www.sumopaint.com/images/temp/xzkaelnnkibopbdq.png The electric current that goes through the 5 ohm resistor is A. 0 A B. 0,3 A C. 0,6 A D. 0,9 A E. 1,2 A Homework Equations 1/Rparallel = 1/R1+1/R2+... Rseries = R1+R2+... The Attempt at a Solution I take the 6...

Hello Forum, When resistors are introduced, it is explained that they can be either in series or in parallel configuration. In series means that the are traversed by the same current and one of the terminals of each resistor is connected to the other's terminal( I am saying that because there...

Hey there! I'm having some real trouble deciphering this complex resistor problem. I have heard of the Kirchhoff voltage and current rules and do know how to use them to solve some problems but I'm not sure how to apply them in this context, or if they are even used to solve this. As seen the...

This is something I have been trying to figure out lately, but I can't seem to wrap my head around it. So, according to a definition in my Physics textbook, while the electrical potential difference established between two terminals encourages the movement of charge, it is resistance that...

Homework Statement http://i.gyazo.com/c6b73ca3a53b7d36bce59a0aa5009d27.png Homework Equations Kirchhoff's Current and Voltage Laws, Resistors in parallel and in Series. The Attempt at a Solution The main thing confusing me is the diagonal 6 Ohms, not too sure what it is parallel too and how...

Homework Statement What is the voltage drop across the 1000 Ohm resistor when capacitor is fully charged? Homework Equations V(t) = {V_i}*e^{-t/RC} = {V_i}*e^{-t/Tau} The Attempt at a Solution In RC circuit experiment, initial is 9V and final is 2V. The voltage drop should be difference...